التغليف (Encapsulation)

class Account:
    def __init__(self):
        self.__balance = 0      # خاصّة (شبه محميّة في Python)

    def deposit(self, amount):
        if amount > 0:
            self.__balance += amount

    def get_balance(self):
        return self.__balance

// Java — private صريح
class Account {
    private double balance;
    public double getBalance() { return balance; }
}

class Person:
    def __init__(self, age):
        self._age = age

    @property
    def age(self):              # getter
        return self._age

    @age.setter
    def age(self, value):       # setter بتحقّق
        if value < 0:
            raise ValueError("عمر سالب")
        self._age = value